I don't know if this is a recent concept or if the suit is just a modern representation of an old one, but when did the devil become the silver tongued businessman in a pinstripe? Specifically, when did we start thinking of him not as the ruler of some underworld, great evil, or a tormenter, but rather as someone who writes contracts and make clever use of legalese?
I know the idea of pacts has existed for a for some time, and the idea that he's a great deceiver even longer, but there seems something particularly modern and distinct about contracts and the willingness to adhere to them.
Specifically, when did we start thinking of him not as the ruler of some underworld, great evil, or a tormenter, but rather as someone who writes contracts and make clever use of legalese?
I know the idea of pacts has existed for a for some time, and the idea that he's a great deceiver even longer, but there seems something particularly modern and distinct about contracts and the willingness to adhere to them.
A deal-making devil, one who uses contracts to seal favours in trade for one's soul, can be found in writing of Archbishop Hincmar of Reims writing in 860 CE and Notker Balbulus in 883 CE. Hincmar writes of a boy who wants the favour of a girl and Satan assists him, the contract requiring the boy to renounce Christ. Balbulus writes of a poor man who gains riches by helping Satan embarrass and ultimately cause the death of a vain, worldly bishop. Both stories feature written agreements.
These are our first recorded instances of what became the early modern Faustian deal, although the general idea of a pact is much older, going back to late antiquity.
The earliest I can gather is the 1937 story The Devil and Daniel Webster.
From there a whole bunch of allegorical stories in that same vein come about, like the legends of singers selling their soul at the crossroads that pervade southern blues culture. Those frequently tell about the Devil wearing a sharp looking suit.
Not sure if this is relevant but I thought i'd throw it in there. In Voodoo Baron Samedi, head of the Guede family of Loa, and a death god and temptor. He is always depicted as a tall thin man with a top hat, black tuxedo (dinner-jacket), dark glasses, and cotton plugs in the nostrils, as if to resemble a corpse dressed and prepared for burial in the Haitian style. He has a white, frequently skull-like face (or actually has a skull for a face), and speaks in a nasal voice. Considering the influential nature of Voodoo culture, especially in the deep south of the US around New Orleans I think that it is quite likely that Samedi's attributes were fused with the Devil and the Devil began to be portrayed with a suit. This is only a theory on my part however.